/* 基础样式 */
body {
    font-family: 'Arial', sans-serif;
    margin: 0;
    padding: 0;
    background-color: #f4f4f4;
    color: #333;
    line-height: 1.6;
}

/* 头部样式 */
header {
    background-color: #333;
    color: #fff;
    padding: 10px 20px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

header h1 {
    margin: 0;
    font-size: 24px;
    font-weight: bold;
}

header nav ul {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
}

header nav ul li {
    margin-left: 10px;
}

header nav ul li a {
    color: #fff;
    text-decoration: none;
    font-size: 16px;
    transition: color 0.3s ease;
}

header nav ul li a:hover {
    color: #ffcc00;
}

/* 主内容区样式 */
main {
    padding: 20px;
    max-width: 1200px;
    margin: 0 auto;
    background-color: #fff;
    box-shadow: 0 0 10px rgba(0, 0, 0, 0.1);
    border-radius: 8px;
}

/* 表格样式 */
table {
    width: 100%;
    border-collapse: collapse;
    margin-top: 20px;
    border: 1px solid #ddd;
    border-radius: 8px;
    overflow: hidden;
}

th, td {
    padding: 12px;
    text-align: left;
    border-bottom: 1px solid #ddd;
}

th {
    background-color: #f2f2f2;
    font-weight: bold;
    color: #333;
}

tr:nth-child(even) {
    background-color: #f9f9f9;
}

/* 表单样式 */
.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.form-group input, .form-group select, .form-group textarea {
    width: 100%;
    padding: 10px;
    box-sizing: border-box;
    border: 1px solid #ccc;
    border-radius: 4px;
    transition: border-color 0.3s ease;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    border-color: #ffcc00;
    outline: none;
}

/* 按钮样式 */
button {
    padding: 10px 15px;
    background-color: #333;
    color: #fff;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.3s ease;
}

button:hover {
    background-color: #555;
}

/* 错误信息样式 */
.error {
    color: red;
    font-size: 14px;
    margin-top: 10px;
}

/* 响应式设计 */
@media (max-width: 768px) {
    header {
        flex-direction: column;
        align-items: flex-start;
    }

    header h1 {
        margin-bottom: 10px;
    }

    header nav ul {
        flex-direction: column;
    }

    header nav ul li {
        margin-left: 0;
        margin-bottom: 5px;
    }
}